Secure short message service

ABSTRACT

A method for sending a secure message within a communications network which operates a short message service (SMS) according to an SMS protocol. The method consists of transmitting an SMS message of a predefined type from a mobile transceiver over the network, receiving the SMS message at an SMS receiver, and transmitting an authorization request, responsive to the SMS message and the predefined type, from the SMS receiver to the mobile transceiver. The method further includes receiving the authorization request at the mobile transceiver, transmitting a pre-determined confirmation code from the mobile transceiver responsive to the authorization request, and forwarding the SMS message from the SMS receiver to a message destination responsive to receipt of the confirmation code at the SMS receiver.

RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional PatentApplication No. 60/326,638, filed on Sep. 24, 2001, and U.S. ProvisionalApplication No. 60/393,454 filed on Jul. 2, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates generally to transmission ofmessages, and specifically to transmission of messages over acommunication network.

BACKGROUND OF THE INVENTION

[0003] Short message services (SMSs) deliver short text messages tomobile transceivers operating in a communication network, and a serviceis implemented in the network according to an industry-standard SMSprotocol. An SMS message typically consists of a relatively small numberof alphanumeric characters, and a mobile transceiver operating in such anetwork may be implemented to receive and/or transmit SMS messages. SMSmessages may also be transmitted to the mobile transceiver in otherways, for example, by generating the SMS message on a computer terminalcoupled to the Internet. The message is then forwarded to a central SMSservice center (SMSC), coupled through a network backbone to a mobileswitching center of the network, via the Internet. The SMSC thentransmits the SMS message to the mobile transceiver.

[0004] The communication network supports both SMS and voicecommunication. In attempting to set up a voice communication, a userinitially makes use of common air channels and computing resources atthe BTS to negotiate a required call configuration. Once the voicecommunication is implemented, dedicated air channels are allocated tothe user for the duration of the call. In contrast to voicecommunication within the network, an SMS message transmission placesconsiderably fewer demands on the network. By its very nature, channelbandwidth for an SMS message is considerably smaller than dedicatedtraffic channel bandwidth used by a voice communication; the amount ofprocessing and number of resources used by the BTS are less than thoseused for the dedicated traffic channel; and time of transmission of theSMS message is considerably shorter than time for a typical voicecommunication. Typically, an SMS message may be transmitted using commonand/or dedicated channels.

[0005] If the communication network operates under a code divisionmultiple access (CDMA) protocol such as the CDMA2000 protocol, publishedas TIA/EIA/IS-2000.5-A-1 by the Telecommunications Industry Association,Arlington, Va., SMS messages are transmitted as data burst messages(DBM) having a pre-defined code.

[0006] Because of the less demanding nature of SMS messages, in times ofhigh overall network demand an SMS transmission may have considerablymore chance of being processed than a voice transmission, sincededicated traffic channels used for the voice transmission may becomeoverloaded while common channels are still available. Such times may becaused by natural events such as earthquakes or floods, or by a man-madeevent such as a terrorist attack.

[0007] However, while SMS messages inherently place less demand onnetwork resources than voice transmissions, SMS messages are less securethan even an unsecured voice transmission. A recipient of an unsecuredvoice transmission is able to judge from the sound if the voicetransmission is genuine; a recipient of an SMS transmission is not ableto form such a judgment. In times of high overall network demand, thepossibility of an incorrect or inadvertent SMS message rises. Thus, amethod for upgrading the security and veracity of SMS transmissions isrequired.

SUMMARY OF THE INVENTION

[0008] It is an object of some aspects of the present invention toprovide a method and apparatus for transmitting a short message service(SMS) message securely.

[0009] In preferred embodiments of the present invention, a mobiletransceiver operates in a communication network, most preferably acellular communication network. The mobile transceiver is configured totransmit SMS messages to an SMS service center (SMSC) in the network,the SMSC being coupled to a mobile switching center of the network via abackbone of the network. Most preferably, the SMS messages aretransmitted using common channels of the communication network. The SMSmessages transmitted by the mobile transceiver may be sub-divided intotwo types: regular and secure SMS messages. A regular SMS messagecomprises an SMS message which the network can transmit according to anindustry-standard protocol under which the network is operating. Asecure SMS message consists of a regular SMS message which alsogenerates an authorization in the SMSC. The SMSC transmits theauthorization to the mobile transceiver on receipt of the secure SMSmessage.

[0010] After receipt of the authorization at the mobile transceiver, auser of the mobile transceiver may transmit a confirmation to the SMSC,verifying that the SMS message is valid. The SMSC waits for theconfirmation after transmission of the authorization. When the SMSCreceives the confirmation code, the service center forwards the verifiedSMS message to its final destination. Providing the capability totransfer secure SMS messages by confirming that the SMS message is validsignificantly enhances the capabilities of the mobile transceiver.

[0011] Alternatively, the SMSC, or an operator thereof, may transmit theSMS message as an unverified message, in which case the finaldestination is most preferably informed that the SMS message isunverified.

[0012] If the final destination of the secured SMS message is notcapable of receiving an SMS message, such as if the final destinationcomprises a landline telephone, a session initiation protocol (SIP)capable phone, a computer terminal coupled to the Internet, or afacsimile machine, the secured SMS message is preferably translated to aform suited to the final destination.

[0013] For example, in the case of the landline telephone, thetranslation is preferably to speech in a text-to-speech converterassociated with the SMSC. The converter is preferably invoked by theoperator of the SMSC, and the speech is conveyed to the finaldestination. In the case of other final destinations, such as thoseexemplified above, the SMSC most preferably utilizes a respectivetranslation protocol to convey the SMS message to the final destination.

[0014] In some preferred embodiments of the present invention, after thesecured SMS message has been conveyed to the final destination, thelatter may generate and transmit a message receipt confirmation. Themessage receipt confirmation is received by the SMSC, which conveys theconfirmation to the mobile transceiver as an SMS message. (Depending onthe type of final destination transmitting the confirmation, the SMSCtranslates the message receipt confirmation to the SMS message.)

[0015] In some preferred embodiments of the present invention, a regularSMS message may be transmitted automatically by the SMSC on behalf of auser of the mobile transceiver. For example, if the operator detectsthat one or more regular voice calls have been attempted by the mobiletransceiver, but have failed to be established, the operator maytransmit a predetermined regular SMS message on behalf of the user. (Itis assumed that the user has chosen to subscribe to this sort ofautomated message service.) This feature of the present invention isparticularly useful, for example, in emergency and disaster situations,in which the cellular network is overloaded with voice calls of userstrying to reach their family members and friends. Alternatively oradditionally, the operator may transmit a suggestion to the mobiletransceiver user to send a secure SMS message.

[0016] In some preferred embodiments of the present invention, a regularSMS message may be transmitted automatically by the SMSC to the mobiletransceiver. For example, a caller may have attempted one or moreregular voice calls to the mobile transceiver, but the calls failed. Thefailures are detected by the operator of the SMSC, who suggeststransmitting an SMS message instead of the voice call. The caller maytransmit the SMS message directly, or the operator may transmit the SMSmessage on behalf of the caller.

[0017] The present invention will be more fully understood from thefollowing detailed description of the preferred embodiments thereof,taken together with the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a schematic illustration of a secure short messageservice (SMS) system, according to a preferred embodiment of the presentinvention;

[0019]FIG. 2 is a sequence diagram showing steps involved intransmitting a secure SMS message, according to a preferred embodimentof the present invention;

[0020]FIG. 3 is a sequence diagram showing steps involved in preparationfor transmitting an SMS message, according to a preferred embodiment ofthe present invention; and

[0021]FIG. 4 is a sequence diagram showing steps involved intransmitting an SMS message, according to an alternative preferredembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0022] Reference is now made to FIG. 1, which is a schematicillustration of a secure short message service (SMS) system 10,according to a preferred embodiment of the present invention. System 10comprises a mobile transceiver 12, operated by a user 20, which is ableto communicate with a base-station transceiver system (BTS) 14.Transceiver 12 and BTS 14 are comprised in a communication network 16,most preferably a cellular communication network operating according toan industry-standard protocol such as a code division multiple access(CDMA) protocol. BTS 14 is coupled to an SMS service center (SMSC) 18via a network backbone 17 comprising a mobile switching center 15. SMSC18 is able to receive and transmit messages according to an SMS protocoloperative in network 16, by methods which are well known in thecommunication network art.

[0023] Transceiver 12 and SMSC 18 are implemented so that thetransceiver is able to receive and transmit SMS messages. Transceiver 12is implemented to transmit the SMS messages as one of two types, regularSMS messages and secure SMS messages. A regular SMS message comprises amessage transmitted according to the SMS protocol operative in network16. A secure SMS message consists of a regular SMS message which isconveyed to its final destination by the SMSC preferably after aconfirmation and verification procedure, described below, has beenimplemented by the user of the transceiver originating the secure SMSmessage; alternatively, instead of performing the confirmation andverification procedure, an operator of the SMSC may intervene to conveythe SMS message. Most preferably, in the case of the operatorintervention described above, a notice is appended to the message sayingthat the message is unverified and should be regarded as such. Bothregular and secure SMS messages are conveyed to a final destination 22by SMSC 18 and BTS 14. Preferably, destination 22 comprises a mobiletransceiver which is able to receive regular SMS messages.Alternatively, destination 22 comprises a receiving device, such as alandline telephone, which is able to receive a communication such asvoice communication transmitted by BTS 14. Further alternatively,destination 22 comprises at least one of a session initiation protocol(SIP) capable phone, a computer terminal coupled to the Internet, or afacsimile machine, and SMSC 18 comprises respective translationprotocols for transmitting to these destinations.

[0024] SMSC 18 is most preferably implemented by coupling one or more“secure-SMS” components 19 to a “traditional” SMSC, i.e., an SMSC thatis unable to support the confirmation and verification procedure. Thesecure-SMS components enable the traditional SMSC to support theconfirmation and verification procedures described below, whileremaining substantially unmodified. Alternatively, SMSC 18 may beimplemented by any other method known in the art.

[0025]FIG. 2 is a sequence diagram 30 showing steps involved intransmitting a secure SMS message, according to a preferred embodimentof the present invention. Steps illustrated in sequence diagram 30 occurwhen mobile transceiver 12 communicates with SMSC 18, which in turncommunicates with final destination 22 of the message. In a first step,transceiver 12 transmits an initiating signal 32 to SMSC 18. Theinitiating signal preferably comprises a text message composed by user20 or a message which has been pre-stored by user 20 in a memory 13 oftransceiver 12, together with a predetermined code which indicates toSMSC 18 that initiating signal 32 is the first step in transmission ofthe secure SMS message. The initiating signal also comprises a telephonenumber of destination 22.

[0026] Alternatively, the initiating signal consists of thepre-determined code only, and a predefined message which has previouslybeen stored by user 20 in SMSC 18 is used as the text for the secure SMSmessage. It will be appreciated that more than one pre-determined code,any one of which is recognized as the initiating signal, may be used,each pre-determined code selecting a different predefined message. Whenthe initiating signal consists of the pre-determined code only, the codealso incorporates the telephone number of destination 22, which isstored by user 20 together with the predefined message corresponding tothe code.

[0027] In a second step, SMSC 18 transmits an authorization request 34,after having received initiating signal 32, and having confirmed thatthe initiating signal is in a form that has been pre-defined at the SMSCfor transferring secure SMS messages. Authorization request 34 isreceived by transceiver 12, and causes the transceiver to emit aconfirmation signal to user 12, indicating that initiating signal 32 hasbeen received at SMSC 18. The confirmation signal may be a visiblesignal such as an indication on a graphic display of transceiver 12, anauditory signal such as a beep generated by the transceiver, or atactile signal such as a vibration of the transceiver, or a combinationof such sensory signals.

[0028] In a third step, after receipt of authorization 34 by transceiver12, user 20 enters a predetermined confirmation code into thetransceiver, and transmits the confirmation code as a confirmationsignal 36 to SMSC 18. The predetermined code has been stored in SMSC 18,preferably by user 20, before transmission of initiating signal 32. SMSC18 receives confirmation signal 36, and verifies that it correspondswith the pre-stored confirmation code. After verification, SMSC 18conveys the secure SMS message to destination 22, as described below.

[0029] Alternatively, rather than performing the second step and/or thethird step, SMSC 18 or the operator of the SMSC may continue directly toa fourth step wherein the message of signal 32 is conveyed onwards. (Thefourth and subsequent steps are described in more detail below.) Forexample, after performing the second step, the operator of the SMSC maywait a pre-set time for confirmation signal 36; if the signal does notarrive within the pre-set time, the operator may nonetheless continue tothe fourth step. Alternatively, after receiving initiating signal 32 inthe first step, the operator of the SMSC may proceed directly to thefourth step.

[0030] Particularly in times of network congestion, such as occur duringemergency situations like a terrorist attack, it will be appreciatedthat user 20 may be able to accomplish the first and third steps withrelatively few keystrokes of transceiver 12. In such a situation, therelatively few keystrokes provide an efficient and effectivecommunication method for user 20 to let a concerned relative or friendknow the user's state. For example, the pre-determined code used in thefirst step may invoke a message “I am well,” and receipt of such amessage will allay the recipient's concern for user 20. It will also beappreciated that, unlike “911” calls which require communication betweenan operator and a caller, transmissions made by user 20 maysubstantially be made on a “send and forget” basis, since a completetransmission, including confirmation, may be performed just usingkeystrokes.

[0031] If destination 22 comprises a device which is able to receive thesecure SMS message “as is,” i.e., in the form of a text message, then ina fourth step SMSC 18 may transmit the message as a text message 38without further operation on the secure SMS message. Alternatively oradditionally, SMSC 18 translates the secure SMS message to a voicemessage, using a text-to-speech translator 24 comprised in the SMSC, andtransmits text message 38 as a voice message 40. It will be appreciatedthat if destination 22 is not a device able to receive text messages,for example if destination 22 comprises a landline telephone, then thefourth step comprises transmission of voice message 40.

[0032] The determination of how to transmit the secure SMS message fromSMSC 18 may be made automatically, for example, if the SMSC and/or BTS14 is able to determine characteristics of destination 22. Alternativelyor additionally, the determination of how to transmit the secure SMSmessage may be made by the operator of SMSC 18. Most preferably, theoperator monitors incoming secure SMS messages, as each confirmationsignal 36 is received, and determines on the basis of the telephonenumber of destination 22 how each secure message is to be transmitted.

[0033] If the second step and/or the third step have not been performed,so that the secure message has not been verified, then, most preferably,in the fourth step an indication that the message is unverified isappended to the message. The indication may take the form of a voicemessage added to voice message 40 and/or a text message added to textmessage 38.

[0034] In some preferred embodiments of the present invention, in afifth step a request for receipt of the secure SMS message istransmitted, as a receipt request signal 42, together with signal 38and/or signal 40. The receipt request signal is preferably appended tosignal 38 as an automatic text message, and to signal 40 as an automaticvoice message. Receipt request signal 42 may be transmitted by theoperator of SMSC 18. Alternatively, initialization signal 32 comprisesinstructions that receipt request signal 42 is sent with signal 38 orsignal 40.

[0035] On receipt of receipt request signal 42, in a sixth step a userof destination 22 transmits a confirmation of receipt signal 44, mostpreferably as a dual tone multi-frequency (DTMF) signal, according tothe request for receipt in signal 42. For example, request for receiptsignal 42 may append a request to the secure SMS message that the userof destination 22 transmits “99#” as signal 44 to indicate successfulreception of the message.

[0036] SMSC 18 receives confirmation of receipt signal 44, andtranslates the signal to a confirmation signal 46 which is sent totransceiver 12. The translation is preferably via a DTMF-to-texttranslator 26 comprised in BTS 14. Alternatively or additionally, thetranslation is to some other form receivable by transceiver 12, such asa predetermined audio signal.

[0037]FIG. 3 is a sequence diagram 50 showing steps involved inpreparation for transmitting an SMS message, according to a preferredembodiment of the present invention. Diagram 50 illustrates steps takenbefore the steps described with reference to FIG. 2 are implemented. Ina first step, transceiver 12 attempts in a call setup attempt signal 52to establish a regular voice call, according to the protocol operativein network 16. In a second step, SMSC 18 sends transceiver 12 anotification signal 54 that the call set up has failed. In a third step,the operator monitoring SMSC 18 sends a suggestion signal 56 totransceiver 12, suggesting that user 20 sends an SMS message. Thesuggestion may take the form of a preset voice or text message totransceiver 12. User 20 preferably then sends a secure SMS message, asdescribed with reference to FIG. 2 above. Alternatively, user 20 maysend a regular SMS message. Further alternatively, in the third step theoperator may send a predetermined SMS message on behalf of the user,providing that criteria previously stipulated by the user in a serviceagreement with an operator of network 16 have been met.

[0038] Particularly when there is a heavy demand on voice channels ofnetwork 16, it will be appreciated that secure SMS messages will have amuch greater likelihood of successful transmission if they are sent viacommon channels, rather than dedicated channels. For example, if network16 comprises a CDMA network, secure SMS messages are preferably sentfrom transceiver 12 using a reverse control channel (RCCH), and messagesfrom BTS 14 are preferably sent using a forward control channel (FCCH).Most preferably, if network 16 comprises a CDMA network, secure SMSmessages are transmitted on the common channels as Data Burst Messages(DBMs) with a dedicated code which has been specifically allocated forsecure SMS messages.

[0039] It will also be appreciated that, especially in times ofemergency or network congestion, an operator of network 16 may changethe balance between common and dedicated channels, so that SMS messagesas described herein have a greater probability of successfultransmission.

[0040] If mobile transceiver 12 is operative in a cellularcommunications network, a location of the mobile may be determined byBTS 14 as soon as a transmission from the transceiver is received by theBTS, by methods known in the art. The location of transceiver 12 may beappended to any SMS message sent from the transceiver, eitherautomatically or via intervention of the operator of SMSC 18. Similarly,a time at which the message was sent may be appended.

[0041] Communication networks typically experience heavy demand on voicechannels in emergency or disaster situations, with users attempting tocontact, or be contacted by, relatives or friends. The heavy demand, atthe minimum, causes long delays in any specific voice call beingsuccessfully negotiated. In many cases the heavy demand maysubstantially “crash” the network. Particularly in these types ofsituations, the contact that is substantially being attempted isrelatively straightforward, where the mobile transceiver user wants tosimply inform family or friends of the user's wellbeing. It will beappreciated that preferred embodiments of the present inventionfacilitate this type of straightforward contact in a number of differentways, e.g., by enabling the user to send a secure SMS message usingrelatively few keystrokes, and/or by suggesting, to the user who hastried and failed to make voice contact, to send a regular or a secureSMS message.

[0042] For example, if user 20 (FIG. 1) is in a region where a disaster,such as an earthquake or a terrorist attack, has occurred, the user maysend a secure SMS message saying “I'm OK,” as described above withreference to FIG. 2 and/or FIG. 3. Alternatively, the operator of SMSC18 may monitor voice calls which transceiver users are attempting toplace from the region of the disaster, and may send a suggestion tousers in the region to transmit a regular or a secure SMS message. Thesuggestion may be sent as a-general suggestion to substantially allusers in the region, or to specific users who have attempted and failedto make voice contact. A location of a transmitting transceiver and/or atime of message transmission may be appended to any SMS messagetransmitted from the region.

[0043] It will be understood that user 20 may indicate to the SMSC 18 anature of destination 22, such as if the destination comprises afacsimile machine or a landline telephone, in order to facilitatetransfer of any SMS message to the destination. Such indication may beprovided during the course of the process illustrated by FIG. 2, and/orprior to implementation of the process.

[0044] It will also be understood that destination 22 may comprise morethan one specific destination, such as a group of family members and/orassociates of user 20. In the case that destination 22 does comprisemore than one specific destination, user 20 may indicate that the SMSmessage is broadcast to all such destinations, or is transmitted insequence to each destination until one of the destinations receives theSMS message.

[0045]FIG. 4 is a sequence diagram 70 showing steps involved intransmitting an SMS message, according to an alternative preferredembodiment of the present invention. The steps comprised in diagram 70occur, for example, when an attempt is made to make a call to mobiletransceiver 12 (FIG. 1) and the transceiver is unable to receive thecall because of congestion on voice channels in the region of thetransceiver. Hereinbelow, by way of example, destination 22 is assumedto act as an originator of the call, which is assumed to comprise avoice call.

[0046] In a first step, destination 22 attempts, in a call setup attemptsignal 72, to establish a regular voice call to mobile transceiver 12.The call attempt is received by BTS 14, which attempts and fails toplace the call, as indicated by arrow 74. BTS 14 is preferably in directcommunication with transceiver 12. Alternatively, BTS 14 is not indirect communication with transceiver 12, but has been informed bynetwork 16 that there is congestion, or a high probability ofcongestion, in traffic to transceiver 12. For example, network 16 mayprovide such information by monitoring traffic statistics in differentregions of the network, and/or by an operator of network 16 becomingaware of an event that could affect traffic, such as a natural disasteror a terrorist attack in the region of the transceiver.

[0047] In a second step, BTS 14 sends destination 22 a notificationsignal 76 that the call setup has failed, and also notifies SMSC 18 ofthe failure. The notifications may be provided via backbone 13 andmobile switching center 15.

[0048] In a third step, SMSC 18 or the operator monitoring the SMSCsends a suggestion signal 78 to destination 22, suggesting that a userof destination 22 sends an SMS message. Most preferably, the suggestionsignal is of a form suited to destination 22. For example, ifdestination 22 comprises a landline phone, the suggestion signal may bea preset voice message suggesting that SMSC 18 sends an SMS message onbehalf of destination 22. Alternatively, if destination 22 comprises amobile telephone capable of receiving an SMS message, suggestion signal78 may be a text message suggesting that destination 22 transmits an SMSmessage which SMSC 18 relays to transceiver 12.

[0049] In a fourth step, destination 22 accepts the suggestion, using anaccept-suggestion signal 80 to SMSC 18, whereupon the SMSC sends an SMSmessage 84 to transceiver 12. SMS message 84 is preferably chosen by theuser of destination 22 from a group of pre-set messages provided by SMSC18, such as “Are you OK?” or “Please call home.” Optionally, anidentifier of the user is added to the SMS message, either automaticallyor via intervention of the operator of SMSC 18. Similarly, a time atwhich the message was sent may be appended.

[0050] Alternatively, if destination 22 is implemented to transmit SMSmessages, it responds to suggestion signal 78 by transmitting an SMSmessage 82 to SMSC 18, as indicated by a broken line 81. SMSC 18 thenconveys the message to transceiver 12 as SMS message 84.

[0051] It will be appreciated that the preferred embodiments describedabove are cited by way of example, and that the present invention is notlimited to what has been particularly shown and described hereinabove.Rather, the scope of the present invention includes both combinationsand subcombinations of the various features described hereinabove,as-well as variations and modifications thereof which would occur topersons skilled in the art upon reading the foregoing description andwhich are not disclosed in the prior art.

1. A method for sending a secure message within a communications networkwhich operates a short message service (SMS) according to an SMSprotocol, comprising: transmitting an SMS message of a predefined typefrom a mobile transceiver over the network; receiving the SMS message atan SMS receiver; transmitting an authorization request, responsive tothe SMS message and the predefined type, from the SMS receiver to themobile transceiver; receiving the authorization request at the mobiletransceiver; transmitting a pre-determined confirmation code from themobile transceiver responsive to the authorization request; andforwarding the SMS message from the SMS receiver to a messagedestination responsive to receipt of the confirmation code at the SMSreceiver.
 2. A method according to claim 1, wherein the communicationsnetwork comprises a cellular communication network.
 3. A methodaccording to claim 1, wherein the SMS message of the predefined typecomprises one of a regular SMS message transmitted according to the SMSprotocol, and a secure SMS message transmitted according to the SMSprotocol after the secure SMS message has been validated.
 4. A methodaccording to claim 1, wherein forwarding the SMS message to the messagedestination comprises conveying the SMS message to the messagedestination as an SMS message.
 5. A method according to claim 1, whereinforwarding the SMS message to the message destination comprisestranslating the SMS message to speech in a text-to-speech translator,and conveying the translated SMS message to the message destination as avoice communication.
 6. A method according to claim 1, wherein the SMSmessage comprises a text message composed by a user of the mobiletransceiver.
 7. A method according to claim 6, wherein the text messageis pre-stored by the user in a memory of the transceiver, and whereintransmitting the SMS message comprises recovering the text message fromthe memory.
 8. A method according to claim 6, wherein the text messageis pre-stored by the user in the SMS receiver, and wherein transmittingthe SMS message comprises transmitting a pre-determined code from themobile transceiver to the SMS receiver.
 9. A method according to claim1, wherein transmitting the SMS message comprises transmitting apre-determined code indicative that the predetermined type comprises asecure SMS message.
 10. A method according to claim 1, whereinforwarding the SMS message comprises transmitting a receipt request tothe message destination.
 11. A method according to claim 10, andcomprising receiving the receipt request at the message destination and,responsive thereto, transmitting a receipt confirmation signal from themessage destination to the mobile transceiver via the SMS receiver. 12.A method according to claim 1, and comprising attempting to set up avoice communication from the mobile transceiver, prior to transmittingthe SMS message.
 13. A method according to claim 12, and comprisingreceiving a notification of a failure of the voice communication at themobile transceiver from the SMS receiver, responsive to attempting toset up the voice communication.
 14. A method according to claim 12, andcomprising receiving a suggestion to transmit the SMS message from theSMS receiver at the mobile transceiver, responsive to attempting to setup the voice communication.
 15. A method according to claim 14, whereinthe suggestion is generated by an operator of the SMS receiver.
 16. Amethod according to claim 12, and comprising an operator of the SMSreceiver transmitting a pre-determined SMS message to the messagedestination responsive to a failure of the attempt to set up the voicecommunication.
 17. A method according to claim 1, wherein transmittingthe SMS message comprises transmitting the message via a common channelof the communications network.
 18. A method according to claim 1,wherein the communications network comprises a cellular networkoperating according to a code division multiple access (CDMA) protocol,and wherein the SMS message is transmitted as a data burst messagehaving a pre-determined code characteristic of the SMS message.
 19. Amethod according to claim 1, and comprising appending at least one of atime of transmission and a location of the mobile transceiver to the SMSmessage.
 20. A method according to claim 1, wherein the messagedestination comprises at least one destination chosen from a groupcomprising an SMS capable cellular telephone, a landline telephone, asession initiation protocol (SIP) telephone, a computer terminal, and afacsimile machine, and wherein the SMS receiver operates a protocolwhich is adapted to translate the SMS message so that the destinationreceives the message.
 21. A method according to claim 1, wherein themessage destination comprises a plurality of specific destinations, andwherein forwarding the SMS message comprises broadcasting the SMSmessage to the plurality of destinations.
 22. A method according toclaim 1, wherein the message destination comprises a plurality ofspecific destinations, and wherein forwarding the SMS message comprisestransmitting the SMS message to at least one of the plurality ofdestinations in sequence.
 23. A method according to claim 1, andcomprising altering a balance between common channels and dedicatedchannels operative in the network so as to increase a probability ofsuccessful transmission of the SMS message.
 24. Apparatus for sending asecure message within a communications network which is adapted tooperate a short message service (SMS) according to an SMS protocol,comprising: a mobile transceiver, which is adapted to transmit an SMSmessage of a predefined type over the network; and an SMS receiver,which receives the SMS message and transmits an authorization request,responsive to the SMS message and the predefined type, to the mobiletransceiver, so that the mobile transceiver is activated to transmit apredetermined confirmation code responsive to receipt of theauthorization request, and so that the SMS receiver forwards the SMSmessage to a message destination responsive to receipt of theconfirmation code at the SMS receiver.
 25. Apparatus according to claim24, wherein the communications network comprises a cellularcommunication network.
 26. Apparatus according to claim 24, wherein theSMS message of the predefined type comprises one of a regular SMSmessage transmitted according to the SMS protocol, and a secure SMSmessage transmitted according to the SMS protocol after the secure SMSmessage has been validated.
 27. Apparatus according to claim 24, whereinforwarding the SMS message to the message destination comprisesconveying the SMS message to the message destination as an SMS message.28. Apparatus according to claim 24, wherein the SMS receiver comprisesa text-to-speech translator, and wherein the SMS receiver forwards theSMS message to the message destination as a translated voicecommunication.
 29. Apparatus according to claim 24, wherein the SMSmessage comprises a text message composed by a user of the mobiletransceiver.
 30. Apparatus according to claim 29, wherein the mobiletransceiver comprises a memory, and wherein the text message ispre-stored by the user in the memory, and wherein transmitting the SMSmessage comprises recovering the text message from the memory. 31.Apparatus according to claim 29, wherein the SMS receiver is adapted topre-store the text message, and wherein transmitting the SMS messagecomprises transmitting a pre-determined code from the mobile transceiverto the SMS receiver.
 32. Apparatus according to claim 24, the mobiletransceiver is adapted to transmit a pre-determined code indicative thatthe predetermined type comprises a secure SMS message.
 33. Apparatusaccording to claim 24, wherein forwarding the SMS message comprisestransmitting a receipt request to the message destination.
 34. Apparatusaccording to claim 24, and comprising receiving the receipt request atthe message destination and, responsive thereto, transmitting a receiptconfirmation signal from the message destination to the mobiletransceiver via the SMS receiver.
 35. Apparatus according to claim 24,and comprising attempting to set up a voice communication from themobile transceiver, prior to transmitting the SMS message.
 36. Apparatusaccording to claim 35, wherein the SMS receiver is adapted to transmit anotification of a failure of the voice communication to the mobilereceiver, responsive to the attempt to set up the voice communication.37. Apparatus according to claim 35, wherein the SMS receiver is adaptedto transmit a suggestion to transmit the SMS message to the mobilereceiver, responsive to attempting to set up the voice communication.38. Apparatus according to claim 33, wherein the suggestion is generatedby an operator of the SMS receiver.
 39. Apparatus according to claim 35,and comprising an operator of the SMS receiver transmitting apre-determined SMS message to the message destination responsive to afailure of the attempt to set up the voice communication.
 40. Apparatusaccording to claim 24, wherein the mobile transceiver is adapted totransmit the SMS message via a common channel of the communicationsnetwork.
 41. Apparatus according to claim 24, wherein the communicationsnetwork comprises a cellular network operating according to a codedivision multiple access (CDMA) protocol, and wherein the SMS message istransmitted as a data burst message having a pre-determined codecharacteristic of the SMS message.
 42. Apparatus according to claim 24,wherein the SMS receiver is adapted to append at least one of a time oftransmission and a location of the mobile transceiver to the SMSmessage.
 43. Apparatus according to claim 24, wherein the messagedestination comprises at least one destination chosen from a groupcomprising an SMS capable cellular telephone, a landline telephone, asession initiation protocol (SIP) telephone, a computer terminal, and afacsimile machine, and wherein the SMS receiver operates a protocolwhich is adapted to translate the SMS message so that the destinationreceives the message.
 44. Apparatus according to claim 24, wherein themessage destination comprises a plurality of specific destinations, andwherein forwarding the SMS message comprises broadcasting the SMSmessage to the plurality of destinations.
 45. Apparatus according toclaim 24, wherein the message destination comprises a plurality ofspecific destinations, and wherein forwarding the SMS message comprisestransmitting the SMS message to at least one of the plurality ofdestinations in sequence.
 46. Apparatus according to claim 24, whereinthe SMS receiver is adapted to alter a balance between common channelsand dedicated channels operative in the network so as to increase aprobability of successful transmission of the SMS message.
 47. A methodfor sending a message within a communications network which operates ashort message service (SMS) according to an SMS protocol, comprising:monitoring one or more attempts at placing a voice call from a mobiletransceiver over the network; detecting a failure to establish the voicecall; and transmitting an SMS message responsive to the failure.
 48. Amethod according to claim 47, wherein detecting the failure comprisesconveying a notification of the failure to the mobile transceiver, andwherein transmitting the SMS message comprises transmitting the messagefrom the mobile transceiver responsive to the notification.
 49. A methodaccording to claim 48, wherein the notification comprises a suggestionto transmit the SMS message.
 50. A method according to claim 47, whereindetecting the failure comprises detecting the failure in an SMSreceiver, and wherein transmitting the SMS message comprisestransmitting the message from the SMS receiver responsive to thedetected failure.
 51. Apparatus for sending a message within acommunications network which operates a short message service (SMS)according to an SMS protocol, comprising: an SMS receiver which detectsa failure to establish a voice call via the network; and a transmitterwhich transmits an SMS message responsive to the failure.
 52. Apparatusaccording to claim 51, wherein the transmitter comprises a mobiletransceiver operative within the network, and wherein the voice call ismade by the mobile transceiver.
 53. Apparatus according to claim 52,wherein the SMS receiver is adapted to convey a notification of thefailure to the mobile transceiver responsive to detection of thefailure, and wherein the mobile transceiver transmits the SMS messageresponsive to the notification.
 54. Apparatus according to claim 51,wherein the voice call is made to a mobile transceiver operative withinthe network.
 55. Apparatus according to claim 51, wherein the SMSreceiver comprises the transmitter.
 56. Apparatus according to claim 51,wherein the voice call is made to a mobile transceiver operative withinthe network.
 57. Apparatus according to claim 51, wherein the SMSreceiver is adapted to: convey a suggestion to transmit the SMS messageto a placer of the voice call responsive to the failure, receive anacceptance of the suggestion from the placer, and transmit the SMSmessage responsive to the acceptance.
 58. Apparatus according to claim51, wherein the SMS receiver is adapted to: convey to a placer of thevoice call a suggestion to transmit the SMS message responsive to thefailure, receive the SMS message from the placer, and convey the SMSmessage responsive to the receipt to a final destination of the message.59. A method for sending a message within a communications network whichoperates a short message service (SMS) according to an SMS protocol,comprising: monitoring one or more attempts at placing a voice call to amobile transceiver via the network; detecting a failure to establish thevoice call; and transmitting an SMS message responsive to the failure.60. A method according to claim 59, wherein detecting the failurecomprises conveying a notification of the failure to a placer of thevoice call, and wherein transmitting the SMS message comprisestransmitting the message from the placer of the voice call responsive tothe notification.
 61. A method according to claim 59, wherein detectingthe failure comprises: notifying an SMS service center (SMSC) of thefailure; conveying a suggestion to transmit the SMS message to a placerof the voice call; and receiving an acceptance of the suggestion fromthe placer at the SMSC; and wherein transmitting the SMS messagecomprises transmitting the SMS message responsive to receipt of theacceptance.
 62. A method for sending a secure message within acommunications network which operates a short message service (SMS)according to an SMS protocol, comprising: transmitting an SMS message ofa predefined type from a mobile transceiver over the network; receivingthe SMS message at an SMS receiver; transmitting an authorizationrequest, responsive to the SMS message and the predefined type, from theSMS receiver to the mobile transceiver; identifying a failure to respondto the authorization request; and forwarding the SMS message from theSMS receiver to a message destination responsive to the failure.
 63. Amethod according to claim 62, and comprising appending a notification tothe SMS message that the message is unverified.
 64. Apparatus forsending a secure message within a communications network which isadapted to operate a short message service (SMS) according to an SMSprotocol, comprising: a mobile transceiver, which is adapted to transmitan SMS message of a predefined type over the network; and an SMSreceiver, which is adapted to: receive the SMS message and transmit anauthorization request, responsive to the SMS message and the predefinedtype, to the mobile transceiver, identify a failure to respond to theauthorization request, and forward the SMS message to a messagedestination responsive to the failure.
 65. Apparatus according to claim64, wherein the SMS receiver is adapted to append a notification to theSMS message that the message is unverified.